I just watched this and it has reinforced my opinion that the Two Knights variation is very underrated at the club level. Grandmasters tend to either ignore it completely in their books or only write a few pages that barely teaches anything on it.
It is a minefield for black. There are so many traps where black is getting checkmated in under 20 moves. Even if black knows and avoids all of them, black only manages to reach a middlegame where he is about equal.
Caro-Kann: Two Knights variation opening traps
Going over tactics more than once is the understatement of the century. When I had my biggest jump in playing strength was after wearing out a few tactics books. Going through them so much that I could instantly see the answer to every problem. And if I'm being honest with you I shouldn't have stopped there, I should have just kept adding more and more tactics books to that list because tactical blunders are still responsible for 90% of my wins and losses if not 99%. Learning positional concepts is nice but it doesn't matter if you can't find the tactics that lead from a superior position. Many times, if you can't find the correct idea (that will usually be steeped in tactics) the opponent will consolidate and you will lose. This is very easy to see with mating attacks and sacrificial play in general. Because attacking the king is actually a positional concept as the most important concept in positional chess is king safety but you won't be able to cash in if you don't know mating patterns and keep missing easy tactics.
Edit: I also think it's better to work with relatively small sets of tactics problems, specifically to ingrain them into your memory. The tactics trainer here can be nice but if you just use it as is, it's more of a test to see how good you are at tactics, not an actual trainer. Although, there are options to limit the set of problems, so using it correctly (imo) can be a substitute for tactics books.